Electrical heating system



Jul 3, 1934.

W. C. CARR ELECTRICAL HEATING SYSTEM Filed Marsh 6, 1953 3 Sheets-Sheet1 INVENTOR ATTORNEY July 3, 1934.

w. c. c ARR ELECTRICAL HEATING SYSTEM Filed March 6, 1933 3 Sheets-Sheet2 NVENTOR M/fz azy C Carr ATTORNEY July 3, 1934. w. c. CARR ELECTRICALHEATING SYSTEM Filed March 6, 1935 3 Sheets-Sheet 3 INVENTOR filya aryflab/7'7 BY 7 ATTORNEY mun Patented July 3, 1934 UNITED STATES PATENTOFFICE 4 Claims.

My invention relates to heating systems, and particularly to systems inwhich electricity is I the source of heat, and in which liquids orvapors or gases are the media employed for transmit- 5 ting the heat tothe point of application.

The object of my invention is to provide a system which may be easilyinstalled; which may be easily transferred from one location to another;in which the heat may be readily and closely controlled; which may beused continuously or intermittently with a very small loss of heat; andone in which the heat generating equipment takes up very small space. Afurther object is to provide a heating system which shall be clean inoperation, which shall require the minimum of attention, in which therewill be practically no cost for repairs, and in which replacements whennecessary may be promptly and inexpensively made. It is also my objectto prov"/30 vide a comparatively inexpensive system both in first costand also in operation.

In the drawings, Figure I illustrates the general arrangement of myheating system, in elevation and partly in section. Figure II shows inplan the heating vessel or pot. Figure III is a broken view, in verticalsection, showing the heating vessel. Figure IV shows diagrammaticallythe arrangement of the heating elements.

In Figure I the numeral 1 represents the end of a standard steamradiator; 2 the steam control valve; 3 the branch steam connection fromthe steam main 4; and 5 a thermostatic valve controlling the flow ofcondensate from the radiator 1 to the return main 6. The steam main 4 isconnected through the valve '7 with the interior of the heating vessel8, which for the sake of brevity and distinction I hereafter call thepot. The pot stands upon a return tank 9. In the drawings the bottomplate of the pot 8 forms the top of the tank 9; but it may be a separate part entirely; that is to say, the closed pot 8 and the closedtank 9 may each be complete in itself. From the inside of the pot adrain connection 11 is made to the inside of the tank 9; and thisconnection is controlled by a cut-01f valve 12 and by a thermostaticvalve 13. If condensate or drip collects in the pot 8 it will be drainedthrough the valve 13 into the tank 9. If it is desired to positively cutoff the connection between the interior of the pot and the interior ofthe tank, the cut 011 valve 12 is closed. Also, by adjusting the openingof the valve 12, the rate of the flow from the pot to the tank may becontrolled. A ball-float 14 is used and adjusted to control the normalwater level Within the tank 9. The level may be high or low, making awet or a dry return. The ball-float valve 15 is connected by the pipe16, through the cock 1'7, with the regular water supply. When thecondensate is returning too slowly from the heating system, the floatdrops, the valve 15 opens, and the deficiency is made up. An overflow 18may be connected to take care of surges; but it is not necessary if thevolume of the tank 9 is made sufiicient. It is best to arrange a vent at19 or at some other convenient place to control the air pressure in theupper part20of the tank 9. This vent is controlled by a small valve 21,so that the upper part .20 of the tank may be used to confine air toform a cushion, which is desirable if a reciprocating pump should beused to pump water from the tank. I have shown a centrifugal pump 22, bymeans of which 'I raise water drawn from the tank 9 through the cutoffvalve 23 and through the connection 24 to the cover 51 of the pot 8. Thepump 22 is driven by the motor 26. The rate of discharge of the pump isreadily controlled by adjusting the opening of the valve 23.

As before stated, the radiator drains into the tank through the valve 5,and by way of the piping 6. In the connection I place one or morecheck-valves 27, to prevent pressure from within the tank acting uponthe thermostatic valve 5, and perhaps building up in the radiationl.

Arranged within the pot 8 are a number of heating elements, 30, 31, 32,33, 34, and 35. These heating elements may be of any suitable form andtype. Those shown are of the round stick type and are known asChromolax. The elements are arranged in pairs in sheaths 36, 37, 38, 39,40 and 41. See also Figure IV. The sheaths are joined at their lowerends by the bends 42. Their upper ends are held in the flange-plates 43,into which they may be rolled or expanded, or brazed, or welded. Or theupper ends of the sheaths themselves may be flanged, as shown in FigureIII at 44. The upper faces of the flange-plates 43 are machined so thata tightjoint may be made between the sheath openings and the openings45, .100 46, 47, 48, 49 and 50 in the cover plate 51 of the pot 8. Theseflange-plates are bolted up to the under face of the cover plate. Thedischarge line 24 from the pump is connected to an opening 52 in the topof the cover plate 51. This opening is connected by a channel 53 to theinside of the first sheath 36.

In the drawings Figure IV shows the arrangement of the sheaths andheating elements and Water channels extended in a row for the sake of 4clearness. The arrangement of the water channels is in Figure IVsomewhat different from that shown in Figure I. In the latter theseconnecting channels are shown formed in the cover plate 51 itself. InFigure IV I show them formed in the flange-plates 43. The difference isa matter of construction; strength; and to some extent, convenience.These flange-plates 43 can also be cast integral with the cover plate51, and the channels either cored or bored. They are preferably bored,and their ends plugged.

Assuming that no electric circuit is completed, and that the elements 30to 35 are not heated: on operating the pump 22 water will be drawn fromthe tank 9, and it will be discharged through the line 24 into theopening 52 in the coverplate 51. The water then passes from the line 24,through the channel 53 to sheath 36, down which it flows, and then upsheath 37, through channel 56, down sheath 38, up sheath 39, throughchannel 57, down sheath 40, up sheath 41, from which it dischargesfreely at the opening 58 into the interior of the pot 8. Thence thewater would flow into the heating main 4. If I am operating the systemas a hot-Water heating system, I either close the valve 12 to preventany flow of liquid and possible pressure from the pot to the tank orvice versa; or I adjust the opening of the valve 12 so that I mayby-pass a part of the water through the tank, and so that I may regulatethe rate of flow through the radiation 1. The temperature of the watermay be rapidly built up by by-passing the water through the short loopconsisting of the heating elements, the pot, the connection 11, thetank, the pump, and again the heating elements. If we close the valve 12the water passes around the longer loop, in which the radiation 1 isinterposed between the heating elements and the tank. By varying theopening of the valve 12 we can vary the volume and also the temperatureof the hot water flowing to the main 4. This can be done manually, orautomatically with the aid of one of the well known thermostatic valves,replacing the valve 12.

The temperature of the water may also be controlled by varying thevolume of heat delivered by the heating elements 30 to 35; and thisagain is readily done through automatic temperature controlled switches,such as the Mercoid. Such switches are arranged to cut in or out one ormore of the heating elements as the temperature of the water falls orrises.

A double control can be had by varying the volume of heat delivered bythe heating elements, and also by varying the volume of water flowing tothe main 4.

Note that the hot water issuing from the opening 58 in the last sheathof the series envelopes the sheaths themselves; and consequently allheat radiated from the sheaths is absorbed by the water enveloping them,until the temperatures are equal. Then as the temperature of theenveloping water increases, heat is given off by the hotter water to thecooler water in the first sheaths of the series.

The bodies of the pot 8 and of the tank 9 are thoroughly lagged toprevent loss of heat as much as possible. The lagging is not shown inthe drawings. It may be of asbestos block, covered with canvas.

When I desire to use my system for heating by means of vapor or steam Ifirst control the flow of water to the pot by adjustment of the pumpdischarge valve 23. The water flows by the same course as noted above;and during its passage through the sheaths it is converted into steam,the point in the series at which the conversion takes place dependingupon the temperatures of the elements and upon the rate of flow of thewater. I am able to so control these temperatures and volumes that I mayhave issuing into the pot at the sheath opening 58 saturated steam atany practicable pressure and temperature, or superheated steam at likepressures and at any practicable superheat.

Note also that the final saturated or superheated steam issuing from theopening 58 envelopes the sheaths, and gives up heat to the water orsteam flowing through the sheaths, pro ducing a regenerative eiTect.Considered from the opposite point of view: there are practically nolosses of heat by radiation, convection, or conduction, except what maybe transmitted through the lagging on the body of the pot.

In the drawings I have shown only six heating elements. The number maybe more or less than six. The size of each element is preferably one ofthe smaller standard sizes; for instance, one having a cylindrical bodyone and a quarter inches in diameter. This is a convenient size for theaverage domestic heating system. With an element body having a diameterof one and a quarter inches I use a sheath having an inside diametervery little more than the outside diameter of the element, such as aseamless drawn tube of a nominal inside diameter of one and a quarterinches, the actual inside diameter of which is 1.368 inches. At thebottom of the U tube formed by each pair of sheaths and the heatingelements can be removed without disturbing any other part.

In Figure I a pressure gauge is shown at 66; and a relief valve at 65.

My heating system can be put to many economical uses in the industries,as well as to the heat-- ing of houses, and public halls or buildings.For instance, there are in some industries demands for intermittentsupplies of superheated steam, or of high pressure saturated steam. Toprovide for such supplies in the regular heating systems in common useto-day would require expensive equipment which would take up much space,and it would result in high operating costs. In such cases my heater canbe used with great advantage; costing little in comparison to the coalor gas or oil burning heater; the upkeep being very small; operationbeing simple; and the usually higher cost per thermal unit being offsetby many advantages, such as cleanliness, portability, small spaceoccupied.

In the claims I have referred to the vessel or pot 8, which contains theheating units, and which forms a small holder in the system, as theheater for the sake of brevity.

I claim:

1. A heater unit comprising a closed vessel divided into a heatingchamber and a returns chamber, and connected to a fluid heating system,the heating chamber to the supply line, and the returns chamber to thereturns line; a trap controlled pipe connection between the heatingchamber and the returns chamber for the purpose of draining the heatingchamber into the returns chamber; a series of connected U tubes withinthe vessel, one end of which series is arranged for connection to afluid heating circuit, and the other end of which series dischargeswithin the vessel; electric heating elements suspended in the U tubesand connected in an electric circuit; and pumping means for pumpingreturns from the return chamber to and through the series of U tubes.

2. A heater unit comprising a closed vessel divided into a heatingchamber and a returns chamber, and connected into a fluid heatingsystem, the heating chamber to the supply line and the returns chamberto the returns line; a trap controlled pipe connection between theheating chamber and the returns chamber for the purpose of draining theheating chamber into the returns chamber; a series of connected U tubeswithin the vessel, one end of which series is arranged for connection toa fluid heating circuit, and the other end of which series dischargeswithin the vessel; electric heating elements suspended in the U tubesand connected in an electric circuit; pumping means for pumping returnsfrom the return chamber to the series of U tubes; and means for addingmake-up fluid to the returns chamber.

3. A heating system comprising radiation, a heater, a heating element,and a fluid heating medium; and a thermostatically controlled bypasssystem around the heater by which, when the temperature of the heatingmedium in the heater is below a certainlevel, the fluid medium isdrained from the heater body and immediately v

